EP0234655A1 - Steilheitsverstärker - Google Patents
Steilheitsverstärker Download PDFInfo
- Publication number
- EP0234655A1 EP0234655A1 EP87200264A EP87200264A EP0234655A1 EP 0234655 A1 EP0234655 A1 EP 0234655A1 EP 87200264 A EP87200264 A EP 87200264A EP 87200264 A EP87200264 A EP 87200264A EP 0234655 A1 EP0234655 A1 EP 0234655A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- transistors
- transconductance amplifier
- ratio
- output
- transconductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
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Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/56—Modifications of input or output impedances, not otherwise provided for
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
- H03F1/32—Modifications of amplifiers to reduce non-linear distortion
- H03F1/3211—Modifications of amplifiers to reduce non-linear distortion in differential amplifiers
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03F—AMPLIFIERS
- H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
- H03F3/45—Differential amplifiers
- H03F3/45071—Differential amplifiers with semiconductor devices only
Definitions
- the invention relates to a transconductance amplifier comprising two transistors T0 each having an emitter area e0, their bases constituting inputs for receiving an input voltage and their emitters being connected to a current source, and further comprising at least a first output for an output current.
- transconductance amplifiers are suitable for general uses and in particular for use in filter circuits, multipliers and oscillators.
- a transconductor is a voltage-controlled current source in which the proportionality factor between the output current and the input voltage is given by the transconductance.
- the simplest transconductor is a differential amplifier, by means of which a voltage applied between the bases is converted into two collector signal currents of opposite phase. In a differential amplifier these signal currents increase as a linear function of the input voltage over a small range only, so that the transconductance is only constant over a very small range of input voltage.
- this known transconductor may be arranged to form a square-law transconductor, in which the output current increases as a square-law function of the input voltage over a specific range.
- the collectors of the transistors whose bases are interconnected are not coupled to each other but are cross-coupled to the collector of the corresponding transistor of the other differential amplifier.
- a transconductor in accordance with the invention it is possible to obtain an output-voltage range which is at least twice as large as that of the known transducers for any value of N by a suitable choice of the ratio between the emitter areas of the transistors and the ratio between the resistance values.
- the manner in which the collectors of the transistors T0 and T1, ..., T N , T N , ..., T1 are connected depends on whether the circuit is to be used as a linear transconductor, in which the output current increases, as far as possible, as a linear function of the input voltage, or as a square-law transconductor, in which the output current increases, as far as possible, as a square-law function of the input voltage.
- a linear transconductor a distinction should be made between class AB and class A operation of the transconductor.
- a class AB transconductor is to be understood to means a transconductor whose bias current increases as the input voltage V i increases, and a class A transconductor is to be understood to means a transconductor whose bias current is independent of the input voltage V i .
- a class AB linear transconductor in accordance with the invention may be characterized in that the collectors of the transistors T1, ..., T N , T N , ..., T1 are connected to a power-supply terminal and in that the collectors of the transistors T0 constitute the outputs of the transconductance amplifier.
- the difference between the collector currents of the transistors T o then increases as a linear function of the input voltage over a specific range.
- the bias current is comparatively small for low input voltages.
- the noise level and the d.c. offset at low input voltages are small.
- a class A linear transconductor in accordance with the invention may be characterized in that each of the transistors T1, ..., T N , T N , ..., T1 comprises two parallel-connected transistors, the collector of one transistor being connected to the one transistor T0 and the collector of the other transistor being connected to the other transistor T0 and in that the collector of one of the transistors T0 constitutes a first output of the transconductance amplifier.
- the output current in each of the collectors of the transistors T0 then varies as a linear function of the input voltage over a specific range, so that each of these collectors may constitute an output of the transconductor.
- a square-law transconductor in accordance with the invention may be characterized in that the collectors of the transistors T1, ..., T N , T N , ..., T1 are connected to a first output of the transconductance amplifier. The output current in the first output then decreases as a square-law function of the input voltage over a specific range. If, in accordance with the further embodiment, the collectors of the transistors T0 are interconnected these collectors may constitute a second output of the transconductor because the current in this output then increases as a square-law function of the input voltage.
- Fig. 1 is the circuit diagram of a class-AB linear transconductor in accordance with the invention.
- the transconductor comprises two transistors T01 and T02 whose bases 3 and 4 constitute the inputs for receiving an input voltage V i and whose emitters are connected to the output 5 of a current source 6 which can supply a current I.
- the emitters of these 2N transistors are connected to the output 5 of the current source 6.
- the collectors of the transistors T01 and T02 constitute the outputs 7 and 8 of the transconductor, whilst the collectors of the transistors T1, ..., T N , T N , ..., T1 are connected to the positive power-supply terminal 1.
- the transistors T1, ..., T N , T N , ..., T1 drain a part of the current I from the current source 6, so that the bias current through the transistors T01 and T02 is only a fraction of the current I.
- the transistors T1, ..., T N , T N , ..., T1 draw an increasingly smaller part of the current I, so that the bias current through one of the transistors T01 and T02 increases.
- the advantage of such a bias current which increases with the input voltage is that for small input voltages V i there will be less noise and less offset than in the case of a constant bias current.
- the difference between the collector currents of the transistors T01 and T02 can be obtained by means of a differential-to-single-ended converter 9 of artibrary construction.
- This converter 9 may comprise, for example, a current mirror, of which the simplest version is shown in the Figure and which comprises a diode-connected PNP transistor T Q1 and a PNP transistor T Q2 connected in parallel therewith.
- the difference between the collector currents of the transistors T01 and T02 can then be taken from the output 8.
- Fig. 2 shows the circuit diagram of a class A linear transconductor in accordance with the invention. Identical parts bear the same reference numerals as in Fig. 1.
- the d.c. component of the currents on the output 7 and 8 is independent of the input voltage V i , which means that the circuit operates in Class A.
- Fig. 3 shows the circuit diagram of a square-law transconductor in accordance with the invention. Identical parts bear the same reference numerals as in Fig. 1.
- the collectors of the transistors T01 and T02 are now connected to an output 7 and the collectors of the transistors T1, ..., T N , T N , ..., T1 are connected to an output 8.
- Both the output 7 and the output 8 may serve as the output of the circuit, the output which is not used being connected to, for example, the positive power-supply terminal 1.
- Fig. 4a shows a class AB linear transconductor in accordance with a first embodiment, which is the simplest embodiment.
- a voltage divider comprising two resistors R0 is arranged, the junction point of these resistors being connected to two transistors T1 each having an emitter area e i .
- these transistors T1 are suitably commoned to form a single transistor having an emitter area 2 e 1, as is shown in Fig.
- the transistor T1 draws 2/3 of the current I from the current source 6 for small input voltages V i , so that the effective bias current is then equal to I/3. At increasing input voltages this bias current increases, which has the advantage that for low input voltages the arrangement exhibits a lower noise level and a lower d.c. offset than the known transductors.
- Fig. 5 shows a class AB linear transconductor in accordance with a second embodiment, identical parts bearing the same reference numerals as in Fig. 4a.
- a resistor R1 is arranged between the bases of the transistors T1.
- Fig. 6 shows a class AB linear transconductor in accordance with a third embodiment.
- the transistors T2 may be combined to form a single transistor having an emitter area equal to 2e2.
- the transistors T3 are preferably also combined to form a single transistor.
- the properties of the class AB linear transconductor in accordance with the embodiment shown in Figs. 4 to 8 are given in the following Table.
- the Table also gives the properties of a normal differential amplifier and the transconductor in accordance with the aforementioned article in the Proceedings ECCTD'83.
- the above Table consecutively gives : the voltage for which the departure from the linear characteristic has increased to 1 %; the current efficiency (C.E.) which indicates the fraction of the current I to which the signal current is equal when the 1 % linearity deviation is reached, and the effective bias current (S) for low input voltages.
- Fig. 9 shows a class A linear amplifier in accordance with a first embodiment, in which Figure identical parts bear the same reference numerals as in Fig. 2.
- One transistor T1 then constitutes the transistor T1 A whose collector is connected to the collector of the transistor T01 and the other transistor T1 constitutes the transistor T1 B whose collector is connected to the collector of the transistor T02.
- the linear range of the arrangement is the same as that of the arrangement shown in Fig. 4.
- the d.c. component in each of the output currents is constant and is I/2.
- the noise and the d.c. offset are therefore higher than in the corresponding class AB transconductor shown in Fig. 4.
- the arrangement shown in Fig. 2 may be constructed as a higher-order class A linear transconductor.
- the linear range then increases in the same way as specified in the above Table for the class AB transconductors.
- Fig. 11 shows a square-law transconductor in accordance with a first embodiment, identical parts bearing the same reference numerals as in Fig. 3.
- the transistors T1 are combined to form a single transistor having an emitter area 2e1.
- the impedances of the voltage dividers in the above embodiments are not limited to pure resistors.
- the transistors shown in the above embodiments may be driven by buffer transistors. These transistors may be employed in a suitable manner in order to reduce the influence of the base currents of the transistors and hence the voltage drop across the voltage-divider resistors on the operation of the arrangement. Another method of reducing this influence will be described with reference to Fig. 12, which illustrates this possibility for the embodiment shown in Fig. 4b.
- the base currents for the transistors T01, T1 and T02 are supplied by a current source 15 which can supply a current I/ ⁇ , where ⁇ is the current-gain factor of the transistors T01, T1 and T02.
- the current I/ ⁇ is applied to a dividing circuit comprising three PNP transistors T20, T21 and T22 having the same emitter-area ratio as the transistors T01, T1 and T02. Consequently, the collector currents of the transistors T20, T21 and T22 are equal to the base currents of the transistors T01, T1 and T02.
- the input voltage range of the transconductor can be extended by not applying the total input voltage but by applying, via a voltage divider, a fraction of the total input voltage to the inputs of the transconductor. This results in a reduction of the effective transconductance.
- the effective transconductance can also be reduced by utilising only a part of the output current by means of a current divider.
- Fig. 13 illustrates this for the transconductor shown in Fig. 9. Corresponding parts of the second transconductor are primed in this Figure.
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Nonlinear Science (AREA)
- Amplifiers (AREA)
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
NL8600422A NL8600422A (nl) | 1986-02-20 | 1986-02-20 | Transconductantieversterker. |
NL8600422 | 1986-02-20 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0234655A1 true EP0234655A1 (de) | 1987-09-02 |
EP0234655B1 EP0234655B1 (de) | 1991-12-04 |
Family
ID=19847601
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP87200264A Expired - Lifetime EP0234655B1 (de) | 1986-02-20 | 1987-02-18 | Steilheitsverstärker |
Country Status (8)
Country | Link |
---|---|
US (1) | US4723110A (de) |
EP (1) | EP0234655B1 (de) |
JP (1) | JPH0834393B2 (de) |
KR (1) | KR960008496B1 (de) |
DE (1) | DE3774896D1 (de) |
HK (1) | HK78493A (de) |
NL (1) | NL8600422A (de) |
SG (1) | SG65793G (de) |
Cited By (9)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0271953A2 (de) * | 1986-12-13 | 1988-06-22 | Philips Patentverwaltung GmbH | Schaltungsanordnung mit steuerbarer Verstärkung |
EP0352790A2 (de) * | 1988-07-28 | 1990-01-31 | Kabushiki Kaisha Toshiba | Integrator und aktives Filter mit Phasenkompensierung |
EP0429717A1 (de) * | 1989-12-01 | 1991-06-05 | Deutsche ITT Industries GmbH | Transkonduktanzverstärker |
EP0597420A1 (de) * | 1992-11-09 | 1994-05-18 | Nec Corporation | Differenzverstärkerschaltung mit vier Transistoren in einer Differenzkonfigurationsschaltung |
EP0603829A1 (de) * | 1992-12-21 | 1994-06-29 | Nec Corporation | Analog Multiplizierer mit Acht- oder Viertransistorstufen |
EP0603942A1 (de) * | 1992-12-21 | 1994-06-29 | Philips Electronics Uk Limited | Transkonduktanzverstärker |
EP0718966A1 (de) * | 1994-12-23 | 1996-06-26 | Motorola, Inc. | Verstärkerschaltung |
FR2761548A1 (fr) * | 1997-03-28 | 1998-10-02 | Sgs Thomson Microelectronics | Etage differentiel a faible bruit et grande dynamique d'entree |
WO2007149117A1 (en) * | 2006-06-23 | 2007-12-27 | Linear Technology Corporation | High linearity low noise variable gain amplifier with continuous gain control |
Families Citing this family (30)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0400650B1 (de) * | 1989-05-31 | 1996-10-09 | Kabushiki Kaisha Toshiba | Linearisierter Differenzverstärker |
GB2234875A (en) * | 1989-07-28 | 1991-02-13 | Philips Electronic Associated | Combined current differencing and operational amplifier circuit |
US4965529A (en) * | 1989-09-21 | 1990-10-23 | The United States Of America As Represented By The Secretary Of Commerce | High current, very wide band transconductance amplifier |
JPH06162229A (ja) * | 1992-11-18 | 1994-06-10 | Nec Corp | マルチプライヤ |
US5525937A (en) * | 1992-12-28 | 1996-06-11 | Sony Corporation | Frequency conversion circuit with UHF/VHF common PLL buffer |
JP2944398B2 (ja) * | 1993-07-05 | 1999-09-06 | 日本電気株式会社 | Mos差動電圧電流変換回路 |
JP2630230B2 (ja) * | 1993-11-10 | 1997-07-16 | 日本電気株式会社 | 増幅回路 |
DE69428785T2 (de) * | 1994-06-30 | 2002-07-04 | St Microelectronics Srl | Aktives Filter enthaltend eine Transkonduktanzschaltung mit hochlinearem Differenzeingang |
US5826182A (en) * | 1995-01-25 | 1998-10-20 | Analog Devices, Inc. | Double balanced RF mixer with predetermined input impedance |
US5815039A (en) * | 1995-07-21 | 1998-09-29 | Nec Corporation | Low-voltage bipolar OTA having a linearity in transconductance over a wide input voltage range |
GB2303507B (en) * | 1995-07-21 | 2000-03-08 | Nec Corp | Low-voltage bipolar OTA having a linearity in transconductance over a wide input voltage range |
JPH09148857A (ja) * | 1995-09-19 | 1997-06-06 | Nec Corp | バイポーラota |
US5933054A (en) * | 1995-09-19 | 1999-08-03 | Nec Corporation | Bipolar operational transconductance amplifier |
US6122497A (en) * | 1997-08-21 | 2000-09-19 | Analog Devices, Inc. | RF mixer with inductive degeneration |
CN1159847C (zh) * | 1998-12-16 | 2004-07-28 | 松下电器产业株式会社 | 带偏置的比较装置及比较电路 |
EP1049249A1 (de) * | 1999-04-30 | 2000-11-02 | Lucent Technologies Inc. | Verstärker mit veränderbarer Verstärkung |
US20020007122A1 (en) * | 1999-12-15 | 2002-01-17 | Howard Kaufman | Methods of diagnosing disease |
US6956407B2 (en) * | 2003-11-04 | 2005-10-18 | Altera Corporation | Pre-emphasis circuitry and methods |
US7239849B2 (en) * | 2003-11-04 | 2007-07-03 | Altera Corporation | Adaptive communication methods and apparatus |
US7196557B1 (en) * | 2004-01-13 | 2007-03-27 | Altera Corporation | Multitap fractional baud period pre-emphasis for data transmission |
US20050160327A1 (en) * | 2004-01-13 | 2005-07-21 | Altera Corporation | Input stage threshold adjustment for high speed data communications |
US7773668B1 (en) | 2004-01-21 | 2010-08-10 | Altera Corporation | Adaptive equalization methods and apparatus for programmable logic devices |
US7675285B2 (en) * | 2004-09-09 | 2010-03-09 | Rockwell Automation Technologies, Inc. | Sensor and method including noise compensation |
US7598779B1 (en) | 2004-10-08 | 2009-10-06 | Altera Corporation | Dual-mode LVDS/CML transmitter methods and apparatus |
JP2008522476A (ja) * | 2004-11-26 | 2008-06-26 | エヌエックスピー ビー ヴィ | 低電圧ミキサ回路 |
US7365570B2 (en) * | 2005-05-25 | 2008-04-29 | Micron Technology, Inc. | Pseudo-differential output driver with high immunity to noise and jitter |
US7265587B1 (en) | 2005-07-26 | 2007-09-04 | Altera Corporation | LVDS output buffer pre-emphasis methods and apparatus |
US7463094B2 (en) * | 2007-03-30 | 2008-12-09 | Don Roy Sauer | Linearized class AB biased differential input stage |
US7733118B2 (en) * | 2008-03-06 | 2010-06-08 | Micron Technology, Inc. | Devices and methods for driving a signal off an integrated circuit |
WO2020235465A1 (ja) * | 2019-05-20 | 2020-11-26 | 日立オートモティブシステムズ株式会社 | 半導体装置および車載用電子制御装置 |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4460872A (en) * | 1981-12-03 | 1984-07-17 | Inventab Audio Kb | Low noise differential amplifier |
EP0157447A1 (de) * | 1984-03-13 | 1985-10-09 | Koninklijke Philips Electronics N.V. | Differenzverstärker |
-
1986
- 1986-02-20 NL NL8600422A patent/NL8600422A/nl not_active Application Discontinuation
-
1987
- 1987-02-17 KR KR87001287A patent/KR960008496B1/ko not_active IP Right Cessation
- 1987-02-17 US US07/015,452 patent/US4723110A/en not_active Expired - Lifetime
- 1987-02-18 DE DE8787200264T patent/DE3774896D1/de not_active Expired - Lifetime
- 1987-02-18 EP EP87200264A patent/EP0234655B1/de not_active Expired - Lifetime
- 1987-02-20 JP JP62035994A patent/JPH0834393B2/ja not_active Expired - Lifetime
-
1993
- 1993-05-20 SG SG657/93A patent/SG65793G/en unknown
- 1993-08-05 HK HK784/93A patent/HK78493A/xx not_active IP Right Cessation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4460872A (en) * | 1981-12-03 | 1984-07-17 | Inventab Audio Kb | Low noise differential amplifier |
EP0157447A1 (de) * | 1984-03-13 | 1985-10-09 | Koninklijke Philips Electronics N.V. | Differenzverstärker |
Non-Patent Citations (1)
Title |
---|
IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS, vol. CAS-31, no. 10, October 1984, pages 891-894, IEEE, New York, US; A. NEDUNGADI et al.: "Design of linear CMOS transconductance elements" * |
Cited By (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0271953A3 (en) * | 1986-12-13 | 1989-08-02 | Philips Patentverwaltung Gmbh | Gain-controlled amplifier |
EP0271953A2 (de) * | 1986-12-13 | 1988-06-22 | Philips Patentverwaltung GmbH | Schaltungsanordnung mit steuerbarer Verstärkung |
EP0352790A2 (de) * | 1988-07-28 | 1990-01-31 | Kabushiki Kaisha Toshiba | Integrator und aktives Filter mit Phasenkompensierung |
EP0352790A3 (de) * | 1988-07-28 | 1991-07-10 | Kabushiki Kaisha Toshiba | Integrator und aktives Filter mit Phasenkompensierung |
US5081423A (en) * | 1988-07-28 | 1992-01-14 | Kabushiki Kaisha Toshiba | Integrator and active filter including integrator with simple phase compensation |
EP0429717A1 (de) * | 1989-12-01 | 1991-06-05 | Deutsche ITT Industries GmbH | Transkonduktanzverstärker |
US5047729A (en) * | 1989-12-01 | 1991-09-10 | Deutsche Itt Industries Gmbh | Transconductance amplifier |
US5381113A (en) * | 1992-11-09 | 1995-01-10 | Nec Corporation | Differential amplifier circuit using quadritail circuit |
EP0597420A1 (de) * | 1992-11-09 | 1994-05-18 | Nec Corporation | Differenzverstärkerschaltung mit vier Transistoren in einer Differenzkonfigurationsschaltung |
EP0603829A1 (de) * | 1992-12-21 | 1994-06-29 | Nec Corporation | Analog Multiplizierer mit Acht- oder Viertransistorstufen |
EP0603942A1 (de) * | 1992-12-21 | 1994-06-29 | Philips Electronics Uk Limited | Transkonduktanzverstärker |
US5389895A (en) * | 1992-12-21 | 1995-02-14 | U.S. Philips Corporation | Transconductance amplifier |
US5581210A (en) * | 1992-12-21 | 1996-12-03 | Nec Corporation | Analog multiplier using an octotail cell or a quadritail cell |
EP0718966A1 (de) * | 1994-12-23 | 1996-06-26 | Motorola, Inc. | Verstärkerschaltung |
FR2761548A1 (fr) * | 1997-03-28 | 1998-10-02 | Sgs Thomson Microelectronics | Etage differentiel a faible bruit et grande dynamique d'entree |
WO2007149117A1 (en) * | 2006-06-23 | 2007-12-27 | Linear Technology Corporation | High linearity low noise variable gain amplifier with continuous gain control |
US7317357B1 (en) | 2006-06-23 | 2008-01-08 | Linear Technology Corporation | High linearity low noise variable gain amplifier with continuous gain control |
Also Published As
Publication number | Publication date |
---|---|
NL8600422A (nl) | 1987-09-16 |
US4723110A (en) | 1988-02-02 |
EP0234655B1 (de) | 1991-12-04 |
DE3774896D1 (de) | 1992-01-16 |
SG65793G (en) | 1993-08-06 |
KR960008496B1 (en) | 1996-06-26 |
JPH0834393B2 (ja) | 1996-03-29 |
KR870008435A (ko) | 1987-09-26 |
JPS62200808A (ja) | 1987-09-04 |
HK78493A (en) | 1993-08-13 |
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